I have a makefile that contains this code
all: hello.exe
hello.exe: hello.o
gcc -o hello.exe hello.o
hello.o: hello.c
gcc -c hello.c
clean:
rm hello.o hello.exe
When i write this command
mingh32-make
I got this:
mingw32-make : *** No targets specified and no makefile found. Stop.
You can solve this in 2 ways.
As the commenters say, rename your file from makefile.txt to makefile.
Another way, use mingw32-make -f makefile.txt
Related
I'm trying to create a makefile titled 'p1' for a project.
When I try the command make p1 it returns with make: nothing to be done for p1
Also, when I try the command make p1 clean it returns no rule to make p1 'clean.' Stop
Here is my makefile:
a.out: main.o P1LinkedList.o const_iterator.o iterator.o Node.o
g++ -std=c++11 main.o const_iterator.o iterator.o Node.o
main.o:
g++ -std=c++11 -c main.cpp
P1LinkedList.o:
g++ -std=c++11 -c P1LinkedList.cpp
iterator.o:
g++ -std=c++11 -c iterator.cpp
const_iterator.o:
g++ -std=c++11 -c const_iterator.cpp
Node.o:
g++ -std=c++11 -c Node.cpp
depend:
g++ -MM main.cpp > p1.dep
clean:
rm -f a.out *.o
What do I need to fix to have the makefile compile .o files from my .cpp files and how do I fix the issue with the clean command?
Edit:
Here are the commands I've used to compile manually:
Helens-Air:p1a helenade$ g++ -std=c++11 *.cpp
Helens-Air:p1a helenade$ ./a.out
^^ and this just continues with the program execution from there
We may have to take this in stages.
First, you seem to misunderstand the difference between a makefile name and a target name. This appears to have been a miscommunication between you and your teacher, but it's easy to clear up.
Suppose you have a makefile named "Makefile", containing the following:
foo:
#echo running the foo rule
bar:
#echo running the bar rule
If you make foo, you will get:
running the foo rule
The argument (foo) tells Make which target to attempt to build. And how did Make know which makefile to use? (After all, you could have a dozen makefiles in the working directory.) You can specify which makefile to use, but if you don't then by default Make will look for a makefile named Makefile (or makefile or GNUmakefile, don't worry about this for now). To specify a makefile with another name, like "Buildfile", you can use the -f flag:
make -f Buildfile
So "p1" ought to have been the name of a target, not a makefile. Within the makefile, rename your a.out rule to p1. Then rename the whole makefile to Makefile. Then
make p1
should work (or at least run).
Edit:
I'll go out on a limb. In the a.out rule (which should now be called the p1 rule), I notice that you have left P1LinkedList.o out of the list of object files to be linked. So try changing it:
p1: main.o P1LinkedList.o const_iterator.o iterator.o Node.o
g++ -std=c++11 main.o P1LinkedList.o const_iterator.o iterator.o Node.o
If that works, you can simplify it with an automatic variable:
p1: main.o P1LinkedList.o const_iterator.o iterator.o Node.o
g++ -std=c++11 $^
And there will be other small improvements you can make.
If it doesn't work, try ls *.cpp and see if you've overlooked some other source file.
Consider this simple example of a Makefile on FreeBSD.
all: hello
hello: hello.o
gcc -o hello hello.o
hello.o: hello.c
gcc -c hello.c
clean:
rm hello.o hello
And whatever I do, change hello.c, or even if I change the content in the Makefile to complete nonsense, make says:
`makefile' is up to date.
What could be an explanation whats going on there?
I guess you have small mess with makefiles. Please note that (for GNU Make): By default, when make looks for the makefile, it tries the following names, in order: GNUmakefile, makefile and Makefile. - make sure you haven't created GNUmakefile`
When it comes to FreeBSD based make it will be: If no -f makefile makefile option is given, make will try to open 'makefile' then 'Makefile' in order to find the specifications.
The only case, I can imagine, follows:
> cat Makefile
all: hello
hello: hello.o
cc -o hello hello.o
hello.o: hello.c
cc -c hello.c
clean:
rm hello.o hello
> make
cc -c hello.c
cc -o hello hello.o
> ./hello
Hello world!
> make clean
rm hello.o hello
> touch makefile
> echo "makefile:" > .depend
> make
`makefile' is up to date.
Basically I am trying to make a simple make file that creates a lexer.o and then a driver.o file combining them into an executable.
Code below shows what has been tried. Running it in Windows powershell using GNU make.
.PRECIOUS = driver.cpp lexer.h lexer.cpp
lexer.o: lexer.cpp lexer.h
g++ -o $# -c lexer.cpp
driver.o: driver.cpp lexer.h
g++ -o $# -c driver.cpp
lex.exe: lexer.o driver.o
g++ -o $# $^
clean:
$(RM) *.o lex.exe
Here is what output is given. I was expecting it to create the lexer.o file, but instead it cannot "find" the file it was supposed to create.
g++ -o lexer.o -c lexer.cpp
process_begin: CreateProcess(NULL, g++ -o lexer.o -c lexer.cpp, ...)
failed.
make (e=2): The system cannot find the file specified.
make: *** [lexer.o] Error 2
It ended up just being a G++ installation problem. I swapped over to Ubuntu and reinstalled everything and it worked fine.
Thanks!, I have updated my makefile now. And the .o are created in the src directory.
here is the makefile and output. The makefile throws the error because all the .o are created in the src folders. I don't know why? I am new to Makefile so kindly please bear with my silly questions.
# This is the Vpath; as my source directory is in the src folder - all the .c files
#folder structure
#Gif_Utility
#-->src/*.c
#-->include/*.h
VPATH = src:include:objects
CFLAGS = -I ./include -g -Wall -DDEBUG
OBJS =./objects
# Look at the CFLAGS here; it has -DDEBUG because in my code, I have #ifdef DEBUG
# Look at the CFLAGS here; -Wall : To generate all the compiler warnings.
# include is required as my compilation depends on the .h files.
# The LD flags to link the shared objects
#LDFLAGS=
#in my mini-project, I am using maths library, Thus, I have lm.
# lc to link my main function with crt1.o
#what is the compiler, am I using.
#This is a good practice since I can modify these flags when cross-compiling.
cc= gcc
#PATH for the LIBS
#This might be useful while cross-compiling.
LIBS= -lm -lc
target: $(patsubst %.c,%.o,$(wildcard ./src/*.c))
#echo "making target"
#mkdir -p ./objects
$(cc) $(patsubst ./src/%.c,./objects/%.o,$(wildcard ./src/*.c)) $(LIBS) -o gif
./objects/%.o: ./src/%.c
#echo "making objects now"
$(cc) $(CFLAGS) $(LDFLAGS) -c $< -o $#
#It is always better to write a PHONY rule for a rules like clean.
#It may happen that in source sandbox, you have a clean file. This may invoke the clean file.
#In order to prevent invoking a clean file during make clean; We give this general rule as PHONY
#PHONY tells the MAKEFILE that there is a rule clean, not a file called clean.
#Generally use PHONY for all, install, clean, distclean,
.PHONY: clean
clean:
#echo "cleaning everything"
#rm -f *.o
#rm -f gif
#echo "clearning .o from src"
#rm -f ./src/*.o
#rm -f ./objects/*.o
$make target
cc -I ./include -g -Wall -DDEBUG -c -o src/sysm.o src/sysm.c
cc -I ./include -g -Wall -DDEBUG -c -o src/x86_main.o src/x86_main.c
src/x86_main.c:11:9: warning: second argument of ‘main’ should be ‘char **’ [-Wmain]
src/x86_main.c: In function ‘main’:
src/x86_main.c:16:9: warning: implicit declaration of function ‘display_init’ [-Wimplicit-function-declaration]
src/x86_main.c:19:9: warning: implicit declaration of function ‘Gif_Read’ [-Wimplicit-function-declaration]
making target
gcc ./objects/gif_display.o ./objects/gif_lzw.o ./objects/gif_read.o ./objects/sysm.o ./objects/x86_main.o -lm -lc -o gif
gcc: error: ./objects/gif_display.o: No such file or directory
gcc: error: ./objects/gif_lzw.o: No such file or directory
gcc: error: ./objects/gif_read.o: No such file or directory
gcc: error: ./objects/sysm.o: No such file or directory
gcc: error: ./objects/x86_main.o: No such file or directory
make: *** [target] Error
You need to fix your patsubst to change the directory part of the filenames as well as the suffixes:
$(patsubst ./src/%.c,./objects/%.o,$(wildcard ./src/*.c))
You have other issues in your makefile too, e.g. this target has the wrong prerequisite:
./objects/%.o: %.c
The source file should be something like ./src/%.c
And the rule for that target is wrong, it outputs to ./objects/$# which would expand to something like ./objects/./objects/x86_main.o
I am having trouble compiling using make in windows 7 with gcc and the gsl library. It occurs only when using make (when I type the compilation commands manually into the cmd line, it compiles correctly). I found some posts where people had similar errors from gcc, but none where it worked when typing normally, but not when using make. The contents of my Makefile are shown below:
#Compiler
COMP=gcc
# Compiler Flags. -Wall turns on all warnings
FLAGS=-Wall
# GSL include file dir
INCLUDES=GnuWin32/include
# GSL Libraries directory
LIB=GnuWin32/lib
# Library Flags
LFLAGS=-lgsl -lgslcblas -lm
# Target Program
EXE=ex2.1.exe
# Dependencies needed for $(PROGRAM)
OBJ=ex2.1.o
# List of source files for objects
SRC=ex2.1.c
# List with types of files to be cleared by clean:
TRASH=*.exe *.o
# I/O files to be cleaned with 'very clean' target
#IOFILES= *.dat *.out *.csv *.mod
all: $(SRC) $(EXE)
$(EXE): $(OBJ)
$(COMP) -L/$(LIB) $(OBJ) $(LFLAGS) -o $(EXE)
$(OBJ): $(SRC)
$(COMP) -I/GnuWin32/include -c ex2.1.c
#$(COMP) -I/$(INCLUDES) -c $(SRC)
clean:
del $(TRASH)
If I type make with only the ex2.1.c present in the directory, I get the following output and error:
gcc -I/GnuWin32/include -c ex2.1.c
gcc: error: CreateProcess : No such file or directory
make: *** [ex2.1.o] Error 1
However, if I first type "gcc -I/GnuWiun32/include -c ex2.1.c", ex2.1.o is created successfully with no error. If then type 'make' I get the following output/error:
gcc -L/GnuWin32/lib ex2.1.o -lgsl -lgslcblas -lm -o ex2.1.exe
gcc: fatal error: -fuse-linker-plugin, but liblto_plugin-0.dll not found
compilation terminated
make: *** [ex2.1.exe] Error 1
But if I manually enter "gcc -L/GnuWin32/lib ex2.1.o -lgsl -lgslcblas -lm -o ex2.1.exe" then the executable compiles and runs like it should, so the problem seems to be with how make is calling gcc? My PATH variable contains the paths to both make.exe as well as gcc.exe, so I am not sure what I do not set up correctly. Does anyone have an idea of what may be wrong? Thanks.